Avian CSI and My Unique Theories

Yesterday was another crests-up day, all day long. The sharp-shinned hawk made an appearance in late morning, but I knew he'd been hangin' around, because there was nothing happening at the feeders, despite the steadily falling snow.

My photos of the sharpie are all terrible, but it's because he's old and wise and he knows to sit well out of camera range. He's no dummy, and he's a good hunter. I've heard a sudden bird squeal from his favorite part of the north border, and on the day I'm chronicling here (November 21), I saw him make a kill.

The jays were merrily feeding, crests straight up, when he came in from the southwest like a blue bullet, looping up just enough to clear the house, then diving on the feeders. He did a barrel roll which bottomed out right in the middle of the jay flock, and came out with something in his fist. My heart was in my throat but I instantly ascertained that his prey was much too small and brown to be a jay. Besides. He's not after jays. He'd have a terrible time subduing one. He doesn't want a fight. He wants food.

I watched him as he took it into the north border and made a mental note to wait a few hours, then go into the woods to try to find the kill site. I wanted to give him plenty of time to consume the bird. Photographers and birders take note: The last thing you want to do is chase and disturb a hawk that's just caught a bird. You could make him drop it, and that would be a very bad thing to do. It would be a waste of a good meal for a bird who needs it badly. Leave him alone. The only look you'll get is him leaving the bird behind.

Sharp-shins are declining precipitously in the U.S., even as Cooper's hawk populations are burgeoning. Why would that be? Aren't there enough feeder birds to go around? The simplest, most surprising explanation would be that Coops have taken to eating their smaller cousins. Terrible thought, but it appears to be true.  I hate it when nature works like that, but it is what it is. It's called habitat partitioning. And it will force the sharpie to live in places where Cooper's hawks aren't. Feeders, thanks to their unnatural concentration of songbirds, bring the two together. As I think about it, most precipitous declines can be traced to an anthropogenic cause. 

As I pontificate on why there are so few sharp-shinned hawks around, realizing that I'm sewing this mostly out of whole cloth, I'm seeing John Cleese as paleontologist Anne Elk, introducing her groundbreaking new theory about the brontosaurus, stridently stating, "This is my theory. It is mine, and I came up with it. It is an original theory, and it is my theory." 

Many thanks for giving delightful flesh to my hazy memory to thenerdist.com

So I was not about to disturb this accomplished little sharpie at his meal. I waited about four hours, then I went out.

It didn't take long to find the shadow of his lunch. The curious will want to click on and embiggen all these photos.

 

Let's have a closer look at that. 

There were only two scraps of anything resembling bone.

 

Mandible, neatly cleaned. Scoop-shaped, conical. So it was a finch. 

Pinkish-red rump feathers. Dull brown flight feathers. It was a male finch. Purple or house? We have both, and their colors have evolved to be nearly indistinguishable here in the East. When they first arrived, house finches were an easily-separated tomato red, to the purple finch's raspberry wine. You could tell people to distinguish them that way, and I did. No more. They're almost the same color now. There might be some adaptive value to cooler reds in the East. Less need to radiate heat? This is my theory, and it is mine. No one else has come up with it, because the theory is unique, and it is mine. Channeling Anne Elk again. Brain on overdrive today.

The answer to the victim's identity is here, in this photo below. Anyone know why?

 

It was a male house finch, because those three buffy undertail coverts to the lower left have brown streaks on them. There are no brown streaks anywhere on a male purple finch. Case closed. Except for cool leftover bits of info.

 Here are the sharpie's droppings. There are almost always droppings at a kill site. 

 

 You can tell they're hawk droppings because they squirt out in a line. Owls drop a puddle, straight down.

 All this took place just inside the woods. That's our garage there, and the yard.

Sharpie knows where the good food is. 

 

I was a little rattled by the close call. What if he'd grabbed a jay? Telling myself he won't. And when I came out of the woods I found big clumps of rabbit fur.  Aww, no. Please no. I can't lose Half-ear Smalley! He's only five months old!

It didn't look good for Smalley. But I searched and found no blood. Just clumps of torn fur. So maybe he survived whatever had happened to him.

Nov. 21, 2018

I didn't see him for a few days. I figured a coyote had nabbed him.

And then on the morning of Nov. 24, he showed up again. 

 

Whewwwww. It is ever thus with rabbits, eminently edible, dear little creatures that they are. They're always looking over their shoulders, and I am too, on their behalf.

I've since found more such fur clumps, with no blood or bone or sign of major struggle, and I have to conclude that the rabbits are fighting these days. Over what, I don't know. Maybe corn.

Please, Nature Gods, don't take Half-ear Smalley. I need warm furry things around to watch, feed and love, even if I can't touch them.

And What Kills the Killer?

If these fitness trackers you wear like a lojack do anything, it's get us out, even when the sky weeps and the chill goes to your bones. I'm thankful for that, though I'm having a heck of a time reaching my daily quota (10,000 steps) when trying to get over a cold. In decent weather, I fly past that picayune mark  every day. 

We went out for a slog through the shredded wheat meadows, trying to keep the dog clean by walking on grass. (I'd just washed him after a muddy run down Dean's Fork). 

It was a day without much visual promise. And those are the kind of days you want to watch out for.

We were coming up the middle path in our field when we all saw this thing lying in the middle of it.

It had been rained on, but by the size and content it seemed to be an owl pellet, a big one.

I started speaking in tongues, the gibberish my family is used to hearing when we've found something BIG. Do you see what I see? I was jabbering in something other than English.

That's the entire foot of a raptor.  In the pellet of an owl. I know it's a pellet because there's very little odor and the bolus is made up entirely of bone and a few digested feathers. It's pretty fresh and quite cohesive. If this were a coywolf dropping, which by its size it'd have to be, there would be colored fecal matter acting as a binder, obscuring the bone fragments, and stinkin' up the place. Plus, I can't see a coyote crunching a raptor's foot down whole. What mammal would swallow talons like that? I mean, besides a Labrador retriever? that was for Floridacracker.

My mind was jumping all over the place. Though I had already figured out whose pellet it was, I was mos def going to figure out whose foot it was. I tried to imagine any owl gagging down the entire needle-taloned foot of a raptor. 

The only owl I could see being able to do that with any aplomb is a great horned. Nope, just can't see a doe-eyed barred owl gagging down a raptor's foot. 

My first thought was that it might be a barred owl's foot, since great horneds are known to prey on all smaller owls. It's a tough world out there. 

By the time we made it back to the house, I'd been turning that pellet over in my hand, and I'd figured out that this was not an owl's foot. How? 

These. These are two rows of scutes, or scales, that run down the tarso-metatarsus (the visible yellow part of the leg) of a hawk. Owls have feathered tarso-metatarsae. The part you can see is covered with fine hairlike feathers. What few scutes they show are all on the foot proper. The exceptions are some of the fishing owls, but they're in Africa, not here. The possible owls here in a meadowy-wooded part southeast Ohio are great horned, barred, screech and saw-whet, and they all have feathered shanks. 

So it's a scaly-legged hawk, with rather long toes. Bird-catching toes.

Bill asked, "You think it could be a Cooper's?"

Synchronicity being the word of the day (remember I'd just photographed that blazing beauty in the birch an hour earlier), I replied, "I think you've got it."

If this was a Coop's foot, it was a big Coop, a female. Just a hunch. I'd have to make some measurements to confirm it.

I thought about how the kill would have been made. The great horned owl, detecting a slight movement or sound from the Cooper's hawk, who was perhaps sleeping tucked into the Virginia pines on our oil well road. Owl flying soundlessly closer. Hearing her breathe, hearing her settle her feathers. Planning its kill. Coming in from behind, strong talons closing around the hawk's skull. Bringing her to the ground, severing her spinal cord with a single nip. The Coop may never have known what took her. I hope she didn't. For what else could kill a big strapping female Cooper's hawk? And how else to do it, but by surprise, in the night? She who surprised songbirds all her life, now facing the last great mystery, and ending up in pieces in an owl's pellet. Egad. I'm glad I sleep in a bed, in a room, in a house, under blankets.

This, amazingly enough, is not the best thing I've ever pulled out of a great horned owl pellet. On the shore of Selden Cove, Connecticut, under  huge hemlocks now long dead at the sucking mouthparts of wooly adelgids, I found the carving block of a great horned owl. And there I found a pellet that had the entire, intact skull and hard beak of a belted kingfisher. Swallow THAT. Great horned owls are the honey badgers of the sky. Great horned owl don't care. She's hungry.

Because I am a Science Chimp, and have been properly permitted to make and store specimens salvaged from window and road kills for most of my life, I happened to have on hand a specimen of Cooper's hawk, and I remembered that it was a large immature female. 

I called out to the kids, "Come down here by the washing machine and I'll give you a lesson in bird foot ID."  Phoebe replied, "Let me tweet that first, and I'll come down." Which made me laugh. She has made a Twitter account called (pardon me) @ShitZickSays

which has a rather intermittent feed, since I'm not the one tweeting away. I have no power there. But I do find it amusing, to have it revealed occasionally what my kids find amusing about me.

I pulled out my Cooper's hawk skin.  Laid the pellet next to it. Talon size looked real good. The big talon you can see in the pellet, that still has its outer sheath, is the inner front toe of the bird's left foot. The one you're seeing clearly on the skin in my hand. That's the killing toe.

Started dissecting the pellet. It smelled, disgustingly and surprisingly, of turkey. Turkey! And Phoebe agreed, recoiling, her nose wrinkling. This gory remnant should not smell like something I eat. I was so glad we'd finally finished the last of the leftover turkey soup from New Year's. I think it's going to be a good solid year before I want to smell turkey again.  Couldn't get it off my fingers...I remember my specimen prep days...yep. That clinging smell. Bleh!

photo by Phoebe Thompson

Back to science. Measured the talons, just to be sure.

photo by Phoebe Thompson

Perfect match. Not only did we have a Cooper's hawk's left foot, but we had a female Cooper's hawk's left foot. The talon in the pellet was ever so slightly longer than the immature bird's talon, which might mean it was an adult bird, but that's farther than I want to take my avian CSI. The foot belonged to a female Cooper's hawk. And that, my friends, is some nice sleuthing. Helps to have the reference resources right on hand, down by the washer...

Even the metatarsal length was perfect. This was a big female Coop. That's a foot-long ruler there. Dorsal view

and ventral view.

Look how perfect that foot is next to the specimen.

Here are the scutes, gleaned from the pellet, that initially told me it was a hawk's leg and not an owl's. I'm holding them up to the hawk's leg so you can see how perfect is the match. 

Just for fun, look at a male sharp-shinned hawk in the same setting.

He's 10" long to the female Cooper's 18 3/8".

Just the foot size difference is astounding. And we get so confused, trying to tell them apart.

Based on what I see on bird ID forums (10 gazillion photos of Cooper's hawks in people's backyards, all of them asking for ID, over and over and over), I have proposed to rename Cooper's hawk "FAQ Hawk."  Think it'll take?

The Cooper's hawk's head.  That rusty flammulation is typical, as are the fine, teardrop breast streaks. Young sharpies look messier, more boldly streaked, and lack the orange flaming.

And her label. Here comes the synchronicity again. Look who collected it. Well, picked it up dead. My dad, Charles Dale Zickefoose, on December 22, 1983. I was 25 and already well versed in skinning and stuffing bird specimens, thanks to experience both in college and in Amazonian Brazil, where I prepared specimens for a small museum at INPA (Instituto Nacional de Pesquisas de Amazonas). I remember her crop being dead empty, no fat reserves, nothing left of her breast muscles, either. She'd burned herself up trying to survive. HY means hatch year. I've got total length (TL), wing chord (WC) and other measurements. A pitiful 12 oz-- a well fed female Coop should weigh 16 oz or more.

On the flip side of the tag, badly oiled by age and fat in her skin, is her story. I found that a small twig had pierced her right eye, blinding her. She was probably diving into thorns to get a bird, James Bond style, and that simple accident ended her career.

I was so honored that my father would think of me and pick her up and bring her to me that I painted a life-sized death study of her, freshly dead. I'd show it to you, but I gave it to my brother. It's nice. I did a lot of death studies back then, learning from the birds how they are built, how things work and go together.  She did not go to waste. Someday she'll go to the Cleveland Museum of Natural History, where they already have probably 150 Zickefoose specimens in their collection.

Here's one from that period of my bird-painting life, a pied-billed grebe that hit a wire in the night and plopped dead onto a golf course in Connecticut. You can imagine what the Cooper's hawk looked like, and see what I learned about it just by painting it, dead. Click on it to read the writing. It's life-size. I still have a penchant for working exactly life-size. It makes sense to me. Look how small the wing is for that dense, compact bird! Look how the legs work--like oars at the stern. Look at the bird of this hour.

I'm still writing everything down, still picking things apart. And that grebe is still with me, like the hawk, stuffed  with cotton and with all its data intact on a tag. I'll save the hawk's leg, too, because it tells a story, and that's what I do.

I watched my little family make their way back to the house on this dreary afternoon.  I lagged behind, shorter of leg, always behind; and now carrying my precious find. 

But I was all lit up with discovery and curiosity, and burning with the certain knowledge that my Dad is still with me, placing inspiration right in my path.

This just in from Facebook friend Steve Huy:

 A friend and mentor of mine, recently departed, 
had studied raptors at the Appalachian Environmental Lab at Frostburg State in MD. His name
was Floyd Presley.

he told me that he was surprised at the number of Cooper's hawk remains they found in barred owl nests

apparently barred owls have a knack for picking off sleeping coops

We don't always know the whole story. We can pick at the edges...

Who Killed That Owl??

Chet Baker and I have been making up for lost autumnal walks lately. On October 12, we ran Pontius Road, then nipped over by car to see what was doin' down on Dean's Fork.

Found an awesome pile of coy-wolf scat, fresh and hairy with raccoon:

That's a big animal. And a whole lotta poo. I forget myself and call them coyotes, but they're closer to wolves out East.  I try to imagine eating raw raccoon with the fur pelt on, and fail. Ugh! But the hair they ingest serves to clean out the digestive tract, much as grass does. They need it.

If you're intrigued by coy-wolves and their prodigious droppings: A little more info, and some of my photos, of who laid that great turd here

We were about to the car when I noticed a stray feather in the grass, one that had belonged to a raptor. I climbed a little rise under a power pole and found a kill scene!

Feathers were strewn everywhere. I could see by their softly fringed edges they were from an owl, and from their color and pattern that they had belonged to a barred owl. Whoa. What would kill a barred owl? I had my immediate suspicions. Let me walk you through my thought process in deducing the killer.

Initially, I was thrown off by the large splash pattern of the feathers, which suggested a mammalian predator such as a bobcat. They were scattered for about 12' around in a big circle.
The feathers were also quite bedraggled and wet, and had been torn out in great clumps. All suggestive of a mammalian predator. But it has been very dewy, so maybe it wasn't saliva that made them so disheveled.

The Bacon didn't think so.

What a mess! A bit of wing. I'm still thinking mammal at this point.

I pick up some wing feathers and examine the quill ends.

The ends are shorn off more or less cleanly, almost as if they'd been cut with a scissors. Or the sharp edge of a hooked bill. 

Had they been chewed off by a mammalian predator, they'd be compressed, flattened, and there would be tooth marks in them. I've swung back to thinking about an avian predator now. But the big splash pattern confuses me. Raptors tend to be neater in plucking than that. I look up and study the power pole above.

Aha! Stuck to a little relay box on the pole are two vital clues: the barred owl's stomach contents (a partially digested katydid), and a clump of plucked barred owl feathers.

I can see that these have fallen from high above and stuck on the plastic box.  Which explains the large splash pattern of feathers--they've drifted down from high above, and spread out. At this point I know that whatever killed that owl bore it up to the top of the power pole to pluck and eat it. So it has to be a bird. There's only one bird that can do that to a barred owl.

With my binoculars, I scan the top of the pole high above. My iPhone can't zoom very well, but that pale thing making an interruption in the shadow near the top is a gauzy buff body feather from a great horned owl, caught on the rough wood. I've got my perp. Great horned owls are hell on all other owls. They're the apex predator wherever they occur, and the first thing they do when they move into an area is clean out the barred owls. Tough but true. It happened on our land.

Lest you feel too sorry for barred owls, out in the Pacific Northwest, they clean out endangered spotted owls. Here they do in screech owls and saw-whets. They'd probably kill a long-ear too. It's a hard world out there, especially at night.

 Dean's Fork is down one barred owl, and up one great horned.

Case solved and closed, and a few more things learned, Chet and I trot for home.

These blazing blue and orange days are few and numbered, and we know it all too well.